Do not assume an official result from a personal decision alone. Determine the appropriate action for the actual stage and retain any official response.
Distinguish intention from completed case action
A preparer closing its engagement is not necessarily the government closing its record. This page does not invent a universal withdrawal form or promise a particular outcome from taking no further action. Stopping contact with a preparer is a private business decision and carries no automatic legal effect on a record held by the government.
Confirm the actual status of the matter through the official channel used to file it, request written confirmation of whatever the current status is, and keep that confirmation with the rest of the file rather than relying on memory of a phone call. A previously submitted application does not withdraw itself simply because no further action is taken, and an open matter can sometimes continue to be reviewed, or can lapse for reasons unrelated to any decision made by the applicant. Where an intention not to continue is genuine, ask what the applicable process is for formally closing or withdrawing the matter, since informal silence is not the same as a recorded withdrawal.
Any processing fee already paid generally remains a completed transaction regardless of a later decision not to continue, so a choice to stop should be treated as forward-looking rather than a way to reverse a step already taken. Keep every notice received, even a notice that arrives after activity has stopped, since a later notice can require a response even when no further action was expected.